Incubator for premature babies



b- 13, 1945- E. L HIGGINBO THAM 2,369,396

HTICUBATOR FOR PREMATURE BABIES Filed Aug. 4, 1940 4 Sheets-Sheet 1 1945- E. HIGGNBOTHAM 2,369,396

INCUBATOR FOR PREMATURE BABIES Filed Aug. 4, 1940 4 ShgetS-Sheet 2 1945. E. 1.. HIGGINBOTHAM I I INCUBATOR FOR PREMATURE BABIES Filed Aug. 4, 1940 4 Sheets-Sheet 3 afy w 3mm nermoswil'cll g 1945' E. L. HIGGINBOTHAM INCUBATOR FOR PREMATURE BABIES 4 SheetS- -Sheet 4 Filed Aug. 4, 1940 Patented Feb: 13,1945

h UNITED STATE 5 PATENT" OFFICE iNooBaron; FOR PaEM TnRaBAm-na a EarnestEhHiggdnbotham; Hybla vane va;

- Application August 4, 1940; Serial' N0. 3'- 51;28 7

' 4.C laims (01. 1285-11 This" invention relates to incubators for use primarily in caring for premature babies;

For such use; an incubator should be so arranged as toproduce conditions most favorable to the babies that are to be cared for in them. i

There arethree vitally essential conditions that must be provided, these being; first; precise regulation of the"- temperature of" the atmosphere that surrounds the baby; second, provisiomof a constant streamof fresh air, to insure a constant supplyof' fresh free oxygen-rand third, regulal tion of the relative humidity of theair towmainjtain it sufiiciently low-to permit normal evaporation from the skin of the baby to regulate its temperature in normal fashion, and sufficiently high to prevent too rapid loss of moisture from the-tissues byevaporation caused bytoo dry air:

use, and which also -permits openingto-a-limited Other conditions that are highly desirable are" movement oftheair within the incubating compartment" at a speed suflicientl'y" lowt0'- avoidturbulence or drafts; and maintenance" of the air surrounding the babyg head at a temperature slightlylower than that surrounding the body, but avoiding sharp l'ines of demarcation between zones of diiferent temperatures. I l

Additionally, such an incubatorshould be" ar= ranged for ready dismantling" so that it can be easily and thoroughly cleaned and disinfected; and should provide for access totheninterior while in operation with l a minimum disturbance of the internal atmospheric condition and a 1 minimum direct communicationwith the cutside atmosphere. l

The chief object offthe' present invention is the provision, in an incubator for" premature babies, of'a novel air-supply system; wherebyar constant}. gentlymoving andnon turbulent stream of air is movedpositively"through the Another object is" to provide incubator for prematurebabies-having a-novel "arrangement for supporting a baby; such arrangement permitting adjustment of the babys position;- and permit ting" ready-"removal of the supportingstructure" to permitthorough cleaning of-*tl"re*interior'ofthe incubator. l

Al further" object is to provide a novel and superior i'ncu'bator fcr premat'ure babi'esi that may be manufactured='- at low cost, and wherein all elements subject to wear or replacement; may be readily and quickly obtained and installed? A still furtherobjectis to provide in anincu baton-{for premature babies-anovel ca-sing struc tune thatpermits full Fopening for access. to'ath'e interior whenthe incubator is'notin incubating extentfor access to theinteribnfor ministrationtotheneedsof ababy -within the-incubating compartment I with a minimum disturbance of the at mospher'ewithin the-incubating chamber.

In the accompanying drawingsz Figure 1" is a perspective-view] of an incubator constructed inaccord'ance -with the-invention; Figure 2- is a front elevation 1 of 5 the incubator with? its front wall removed! Figures 3 and 4" are sectional views on lines 3-3 andM Ur-espectively of"Figure -2 Figure=-5 is a fragmentary perspective view oi a" portion ofan endof the incubator".

Figure 6 isa fragmentary'bottom planwiewmf the table-support: l 1

Figure 7 is an elevation of a specialized fan for use in theincubator: l l

incubation compartment, and whereby the rate of flow of such stream of air is awh'ollyin dependent% of and unaffected by external conditions or temperature. l

Another: objectisthe'provision'in such an incu- 3 bator of" novel means for producing within the incubatingcompartment' a relatively large' reg-ion' of substantially constant and uniform tempera ture, such regionbeing substantially that 'in which the-body oi ababy positioned, and asmaller" region of' a temperature a few degrees lower, for reception-of the babys head, anda graduated temperature region regions. first-mentioned; l

Still another objectis'to-providaa novel heat humidifier unit for: use in the incubator.

Eigure 9 is a plan view of such unit; FigurelOfiis-a wiring diagram: Figure L1 is air ihterior-plan of the door :assenrbl'yr q l t Figure 12- is a detail sectional view-on line I 2--l-2"o1- Figure 11;

Figures-- 13 and are detail broken perspec' ti'v'e vi'ews showing the door assemb'ly operr'and cl'osed lpositionsa between the two ing and humidifyingsystem forconditioning air" tmbe supplied to the -incubating chamber:

Flgurelh" is a sectiona1'--view' on' line I*5"-I5 of FigurelZ. Figure 16 isa sectional-"vi'ew'on'lin Figural-2. t

Figure 17 "isa: sectio'nalviewwnf line? I'l -l 1 of Fi'gure l2l Describing the drawings'more particularly; the numeral-2 0 indicatesgenera-lly a'casing'compris 7 ing abottom wal -2 1; a lowervertical-front wall 22", an i'nclilrled upperfront wall? 2 3, arre'a-nwall Figure 8 is an end? elevation-- of a specialized 24, a top wall 25, a foot wall 29,, and a head wall 21. With reference to the terms head and foot, it is to be understood that they are used to indicate the respective end portions of the incubator within which the head and feet of a baby are intended to be placed, or the walls that close such respective ends.

The space enclosed by the casing is longi-' tudinally horizontally divided into a lower air conditioning chamber 28 and a superposed incubating compartment 29, by a horizontally disposed table support 39 that extends longitudinal- 1y between the head and foot walls. The support 39 is supported by transverse members 3| upon which the ends of the support 39 rest and which members 3| are respectively mounted on the end walls 26 and 27. The members are mounted by removable pins 30a that penetrate the members adjacent the front wall-22 and extend into sockets in the end walls, and pivot members 3922 adjacent'the rear wall 24. As it is often desirable to maintain a baby in an inclined position, the support 39 at each end is provided on its under side with an extensible pin 32 that may be engaged with any one of a series of vertically spaced sockets in the end walls 26 and 21. The pins 32 being centrally located on the support 30, when one end of the support is raised above its supporting member 3|, the support 30 is maintained against transverse tipping by the engagement of the opposite end upon its supporting member 3|.

The table support 30 is narrower than the distance between the side walls 22 and 24, and its edges are spaced from the inner surfaces of such walls, leaving longitudinally extending slots 35 that communicate between the chamber 28 and the incubating compartment 29, such slots extending continuously between the foot wall 26 and the head wall 21. Reticulated guards 36 are hingedly and detachably secured to the upper surface of the support 30 adjacent its edges 34 by curved pins 31a that engage over a lower frame member 37 of the guards, the pins penetrating the reticulated guards above their lower frame members to provide pivotal mounting of the guards'about their lower frame members. This arrangement permits the guards to be swung from an operative position guardin the slots 35. to an inoperative position, shown by the dotted lines, wherein the guards are collapsed on the surface of the support 30. The guards may be removed from the support 30 by sliding tion, the outer edges of the guards rest against the inner surfaces of the side walls 22 and 24 above the slots 35.

To furnish an accurately conditioned supply of v them off the pins 31a. When in operative posiair to the incubating compartment 29, the following system is provided. Adjacent the foot wall 26, and within the air-treating chamber 28, is a pair of air-heating devices, preferably light bulbs 38 secured in sockets 39, said devices being spaced apart transversely of the chamber 29 and located adjacent the side walls 22 and 24, and being mounted on the foot wall 26. Between the heaters 38, and adjacent the foot wall 26, is a specialized humidifying device 40.

'As best shown in Figures 8 and 9, the humidifying device comprises a water tank 4| provided with a filling spout 42, which may be provided with a closure 43 hinged to the spout at one side of the opening and shown swung to its open position in Figure 8, and that extends through the foot wall 26. Thetank 4| has a side wall 44 to which is secured a laterally extending arcuate screen 45, the distal edge of which i secured to a supporting leg 46. An electric bulb 41, or other heating device, is arranged beneath the screen and between the wall 44 of the tank and the leg 46. The tank 4| is provided with a top wall 43 that is removably mounted on the tank as by hinging to one side wall thereof. The side wall 44 is, immediately above its juncture with the screen 45, provided with a slot 49, through which a cloth 50 extends into the tank. The cloth is spread over the upper surface of the screen 45. In operation, the cloth '50 is maintained moist by capillary attraction, and-the moisture is evaporated by heat from the heater 4?. Since, as will be later described, a definite volume of air per unit of time is moved over the surface of the cloth 5|], and since the humidifying capacity of the device 40 is directly proportional to the area of cloth exposed to the air,-the humidifying effect of the device can be adjusted by adjustment of the size of the area of cloth exposed.

The humidifying device 40 may be removably mounted .by means of laterally extending fins 5| slidably engaged beneath flanges 5|a that are secured to the bottom wall 26 of the casing.

To provide a continuou and regular flow of air through the incubating compartment 29 an air outlet 52 is provided in the head portion of the compartment, preferably in the head wall 21 adjacent its top. With the outlet 52 is associated an exhaust fan 53 driven by a synchronous electric motor of the kind commonly used in elec- The assembly'is best illustrated in out .by a manual switch 55. Simultaneous operation of the heaters 38 and 4! is controlled by a thermostatic switch 56. The motor of the fan 53 is connected across the circuit for constant operation independent of the switch '56, and may be separately controlled by a manual cut out switch 51. The circuit also includes an illuminating bulb 58 controlled by a manual switch 59.

Referring to Figures 2 and 4, it will be seen that the thermal-responsive element 69 of the thermostatic switch 56 is located in the foot portion of the incubating compartment 29, preferably being mounted on the foot wall 29. A manual control 6| for adjusting the operating temperature of th element 60 is arranged exteriorly of the wall 26. The thermostatic switch 56 is preferably of the micro-degree sensitive type that is commercially available.

The illuminating lamp 58 is conveniently located' centrally of the incubating compartment 29 adjacent its top and mounted on the rear wall 24, the switch that controls it being operated by an external button 62. The fan motor cut out switch 51 may be operated by an external button 63.

In the foot wall 26 are provided air inlets 64,

and humidifier 40. Air inlets are provided in the head wall 21, such inlets also entering the chamber 28. Guard rods 66 are preferably arranged adjacent the inlets 65 of the head wall,

for a purpose to be described later.

The operation of the apparatus so far described ly, and draws air from. the incubating" comparte menti atta constantrate sufiicient, to; insure an 3 ample supply ofyfresh air; yet sufiicientlwlow to. avoid; drafts within; the compartment. The:

will be readilyqunderstoodt. nurinaactualion a tiontof theiin ubatonthe fan operates: continuous ratecf-flcwthrougn theincubatingreompartment isunafiected; by variations in external temperationcurrents for circulation. I i L When the deviceisnoti in actual operation;

wi h

i may be kept in idling condition, ready foriinstant use, by cutting out the; operation of;;the,,fan' while the heatersand humidifier are left. in operation ture; conditions, which variationsexertan effect.

uponthe, air flow indevices relying; uponconvec, f

undercontrol ofv the thermostaticrswitchrx Dun-t ingsuch idling, the air within; the; incubating; compartment 291 and air-conditioning chamber 28L-wi1lbe kept at proper temperature and relaitive humidity with a minimum amount of open ation of the conditioning devices 38 and dfl, re-

suiting. inta minimum consumption of. current.

When the, incubator is-placed inservice all that is necessary isito startthe, fan. The switch 51 ishprovidedtow enable this idling inreadinessffor instant use.

a The organization head; of the incubating, compartmentz 9, the heat,-

ing and humidifying devices at the. foot of theairetreating chamber 28, the air inlets Bland 65 or the air outlet .52.: atthe,

atithejopposite ends of,the, .latter chamber, and i the longitudinal SIOtSQiBXtE-Zllding the lengthof devices at the foot endof the.airti'eating,cham-- ber causes the "air that enters by the inlets, to

be treated, so that heated, and moistened, air is present infthe foot portion of the chamber 218.

while air at a,lower temperature, having entered atga distancelfrom the heaters, and humidifier the; interior, of the incubator, all cooperate; to i provide the proper zones o'fvariations in temperature within the. incubating compartment.

35; Thearrangement offthe heating and humidifying i the guards 3-6 are removed from the support, the pins 30a that support thefront ends of the trans cupantisu'headxtcbasurrounded by: air: that iszsev eral j degrees-zcooler than: that which surrounds.

body; withouti'therezlbeing a; too sharp? line of demarcation between the two zones, andfwithcut: theznecessity of partitioning theincubating compartmentt to maintain the two zones of different:

temperatures. i

Thersimultaneousoperation of theiheatingz'andt humidifying vdevicesaffords an accurate control of; the relative; humidity. Relative humidity bee ingv ahfunction of the temperature, when-the humidifier: is: set in operation at the same instant that'the heaters commence operating, the humidity is increased as the temperature isin creased; The arrangement of the heating and humidifyin'gdevices in close proximity contributes to the uniformmaintenance of the: relative humidity... A relative humidity of from 55 to- 65" percent satisfies optimum conditions for the care iof premature infants. By selecting the; size of" the exposed area ofvthe cloth 501' with relationto the rate of air flow induced by the fan 53, the

humidity can be readily maintainedwithinthese limits; and, except under external conditionsof zsiexcessive humidity, when itis desirable to cutv out the operation of the humidifier, the relative humidity within the incubating compartment will not be affectedby external humidity conditions. i i A door -81, that extends longitudinally thefull length' of the casing ;,isarrangedin the lower move. the table support 3llflfromthe incubator,

verse members 3 I are withdrawn; permitting the assembly-of members 3| and suppcrt Slam i Di-about the pivots b to the dotted linegposition of Figure 3; after which the support 30rnay be slid from themembers 3l through-the door 613' ispresentin theheadfend. ofthe chamber. This latter ain is heated to someie xtentflby radiation from the heaters 38 and also by mixture. with, the heated air from the footend of the chamber.

Since the exhaust fan 52 islocated in thehead It" is? desirable in anincubator of this kind y particularly one that" is readily portable, topro: vide for emergency use Where electric current is" not available; In the present incubator suchemergency use can be accomplished byremov end of" thecompartment 2,9,theair, isdrawn tojwards that end from both ends of the chamber as; resulting in upwardiangular, flow throughthe slots throughout the length oflthe incubator. The distance between inlets 65 in the head wall 21 and the outlet 52 being appreciably less than the distance betweentheinlets Min thefoot' wall and the cutlet the cooler air that has entered the chamber 28 by the inlets s5 willjtend to remain within a limited distance of the head wall 21;

while the more highly heated andhumidified air that entered by the foot inlets lildtraverses the entire lengthof the incubator and'flows upward" along variousangularpaths, along the slots 35'.

These flows are indicated by the arrows in Figure 2. It will beseen fromthisfifigurej that adjacent the ,foo twall 26 within the compartment, there is: a relatively long zone; wherein the air is a1":

most exclusively that which has been subjected to vthe actionmor the treating devices 38'and 40; thatfadjacentthis zone there is a shortintermediate/zone wherein the proportion ofair that has, entered by the head wall inlets: 65 increases sharply, and that adjacent the; head wall; 21-

into the chamber- 28; byway of the door 61.2 The guards- 6'6 arranged adjacent the inlets 6'5 in: the

headwall prevent the bottles from approaching the inlets sufficiently to interfere withthe entry of .air, the sockets39 adjacent the fOOtWELIl serving the same purposewith relation to the inlets 641; This isof importance when the incubator is being moved about.

During-use with heating by! water bottles, air. flow isaccomplishedb-y convection currents. By actual testit has been established that by usin a number of one-quart standard Mason type jars filled with waterat the desired temperature and renewedat one hour intervals; the temperat there is a third zone, adjacent the upper surface cf the ,tablesupport 3ilwherein therairis largely thatwhich has entered byythe inlets This zone arrangement permitstheybaby cc ture of the incubating compartment is main-- l taine'dsuiiicient1y"constantforpractical use. It

has also been found that there i sufiicient evaporatiomfrom such jars provided with the usual packing rubbers and top screwed on'handtight a maintain'the humiditywithin satisfactory limits".

described, it vdoes perrnit' use where electricityis notiavailable, and it permits transportation of the -incubator wl'nle in actuali satisfactory-op vertical front 'wall 22, being hinged to the bot tom wall 2| at 68; and springlatch devices 659 are arranged upon the endl walls 26 an'd 2 'l for. holding the door 66 in-closed-position; To reingbottlesof water at the" desired temperattu e Whilesuch use does not give the precise control" of temperature and humidity that is achieved-by using the el'ectric system previously eration. It also is highly advantageous that the same incubator may be quickly and readily transferred from one type of Operation to the other, as permitted by the arrangement just described.

In Figures 11 to 1'7 is disclosed a door assembly that is specially and peculiarly adapted for use in an incubator of this kind. The inclined upper front wall 23 comprises an upper longitudinal rail member it and a lower similar member H, which members are vertically spaced apart. A pair of doors 12, that are slidable between the rails 1i] and H, are movable longitudinally of the casing from a closed relation with their adjacent edges in meeting relation to an open position to give access to the interior of the incubating compartment 29. The doors 72 are provided with observation panels 13 of shatterproof glass. Vertical handle slots 14 extend completely through the doors 12 adjacent their inner edges, for a purpose later to be described.

in order to provide an opening, smaller than disturbance, an automatic guard assembly is or.-

I ganized with the doors 72.

Guard plates 1-5 are supported in face to face relation with the inside surfaces of the doors 12, the vertical extent of the plates being of such size as to cover the upper portion of the open- 'ing provided by the doors 12, and leaving below their lower edges only suiiicient opening to permit access to the interior for performing such operations as are necessary.

The guard plates 75 are provided with spring latching means for releasably holding together their adjacent edges. Such means may advantageously be in the form of offsets Hi and H adjacent the meeting edges of the respective plates 1'5 and arranged to interengage to lock the plates together, and inclined portions i8 and i9 so ar-v ranged to permitthe edges of the plates to override and spring into locking engagement when the plates are moved together. The plates 15 are supported by cover blocks 80 and 8! having ledges 82 that slidably engage the under edges of the plates'15. The blocks BI! and 8| are secured to the respective doors 12 as by screws 82a extending immediately above and below the low er edges of the plates 15. The edges of the plates 15 are provided towards their outer edges with extensions providing stops 83. When the doors l2 and the blocks -88 and 8! that are secured to them are moved in the directions towards their open positions, the guard plates i beingin interlocked condition, the stops 83 engage with the screws 82 and thereby limit the opening movement of the door to limit the longitudinal extent of the opening that is afiorded, the vertical extent'of such openingbeing limited by the guard plates.

The meeting edges of the cover blocks 80 and 8! are respectively provided with recesses 84 and 85 for the reception of the locking structures it, 17, I8 and 19 when the doors are in closed positions. The recess 85 is bevelled off suificiently to permit the marginal portion of the plate 15 with which the block 8! is associated, that portion including the innermost locking structure, to be moved inwardly of the casing to release, the cfiset 16 from the offset F5 to disengage the locking engagement between the plates sothat 75 5 effecting this release.

that afforded by 'moving the doors [2 to their bating chamber will be subjected to a minimum they may move with the respective doors (2 to permit full opening of the incubator. A push button 86 extends through the door 12 behind which the movable structure 76 and 18 is located for Springs 87 maybe interposed between the block 8| and its guard plate 15 to secure the interlocking engagement of the edges of the plates. Strips 88 are secured to the outer edges of the blocks and 8| to engage the outer edges of the plates 15 as the doors are moved towards closed position and move the plates to interlocking position after they have been opened. 7

It will be noted from Figure 14 that the handle slots 14 of the doors 12, being open completely through the doors, expose areas of the guard plates 15. Suitable colored areas of the guard plates may be arranged to be exposedby the slots when the doors are in certain positions relative to the guard plates, to afford signals of such relative positions. e

The closure assembly just described provides for automatic interlocking of the guard plates when the'doors are moved to closed position. after which, opening of the doors results'in the exposure of the opening that is limited to a size necessary for reaching into the incubating chamber for treating the occupant. When it is desirable to completely open the incubator, it is necessary to press the releasing button to disengage the guard plates, after which they move with the doors, permitting the doors to be moved I to their fully open position and also open the guard plates. This arrangement efiectively prevents accidental full opening of the incubator with an attendant disturbance of the internal atmospheric conditions. From the foregoing the construction, operation and many advantages will be readily apparent to those skilled in the art; and it will be understood that changes in the size, shape, proportions and minor details may be resorted to without sacrificing any of the advantages of the invention or departing from the scope thereof as set forth in the appended claims.

I claim:

1. In an incubator for premature babies, said incubator including in superposed relation an incubating compartment and an air-supply chamber, means for supplying heated air to one end only of the air supply chamber and unheated cating between the compartment and chamber and extending substantially from end to end of said compartment.

3. A, horizontal partition in accordance with claim 1, said partition being of less width than the chamber and compartment andhaving its said partition being of less width than the chamher and compartment andhaving itsedges spaced inward from the sides of the incubator, said partition being nwideenoughito support a baby on its surface within the incubating compartw ment, said partition being removably mounted between the compartment andehamber, and reticulated guards extending from end to end along the respectiveedges of the partition, said 2,369,396 p a a j guards being pivoted horizontally to the partltion adjacent its edges, and said guards being of sufficient width to be swung into engagement with the walls of the incubator above the spaces between the edges of the partitionand the walls of the incubator when the partition is mounted within theincubatorfl a i EARNEST HIGGINBOTHAM. 

